I have noticed several players rostering additional characters with just one colour of cover to send as team ups (to guarantee colour received). I have seen thus with:
1* BW (blue)
3* Deadpool (Purple)
3* Punisher (Red)
Which other characters would players recommend for targeted Team-Ups ?
1* Spiderman with 5 purple is a stellar teamup for 5* users. Crits with 5* match damage are bonkers.
Ghost Rider Black is the main one that comes to mind that hasn’t been mentioned yet.
Juggs green. With 5 covers of course.
Bag-Man’s yellow (which increases friendly countdown timers) is actually a really helpful team-up with certain characters. However, I have been working on a yellow-only Bagman for at least four months; I play PVP fairly regularly and I have earned exactly one yellow Bag-Man cover in that time.
Yeah higher level, crits are game changers. I’m only in the 4* transition, and it makes a huge difference. One reason why Jean Grey is popular I think.
I can’t get enough GSBW purple team-ups. I love those.
You don’t need a dupe for that, red can’t be sent (because of self-damage). 5/5 Juggs will always give green as team-up.
Wow… +4 turns on SpiderWoman’s black? 8 turns of some serious damage mitigation. Gotta love that.
I send out medusa sometimes. She only has one active so I know they are getting that. It’s good against goons.
Loki trickery is a great TU.
btw you always send 5 color max levels no matter what. level will go over max level (based on your top 3) if sender characters are championed.
Yeah, but usually you have no control over which power is sent… so in some cases a 5/0/0 dupe is worth having solely for TU purposes.
Some great underutilized ones, in my opinion:
2*
3*
4*
i mean if u send say modern black widow with 1 blue, it will always send a 5 blue team up.
Not yet mentioned: Quake (aoe damage+board shake), JG, Wolverine (black can be pretty deadly) and sw come to mind. Any 4* boosted can be a good TU too.
No, it won’t. She obviously isn’t champed. I had alliancemates send me undercovered MBWs (0/3 or something like that) and the TU was at only 3 covers. The always-5-covers rule applies only if you send a champed character.
If you send a 0/1 MBW, you’re a bad person. 
I was pleasantly surprised to learn that Mr. Fantastic is actually a fantastic TU to send. (Pun intended) He only sends out blue which is a nice, cheap stun and targeted swap.
Thanks for the ideas, some real food for thought .
Cheers.
Moonstone black
Moon Knight green - I got a Moonie TU which dealt 62k damage
Many 4*s have strong TU’s when boosted tbh
Luke Cage’s Righteous Uppercut I think counts all three characters as allies when used as a team-up. When a Luke Cage in your team uses it, he doesn’t count himself.
Similarly, Gwenpool’s Plot Armor will send all your characters airborne when used as team-up. When used by a Gwen in your team, she remains a target.
Maybe not the best team-ups, but a couple that are or could be better when used as a team-up. Hood yellow could fit here too.